Economic Evaluation of Selected Interleukin Inhibitors Versus Methotrexate for Moderate-to-Severe Plaque Psoriasis From the Philippine Payer Perspective.

ABSTRACT

OBJECTIVES: We conducted an economic evaluation of interleukin inhibitors (ILIs) guselkumab, ixekizumab (IXE), secukinumab (SEC), and ustekinumab to a methotrexate (MTX) comparator for biologic-naive adult Filipino patients with moderate-to-severe chronic plaque psoriasis. METHODS: A 1-year decision tree and 5-year Markov model were used to estimate incremental cost-effectiveness ratios (ICERs) in Philippine pesos (PHP) per Psoriasis Area Severity Index improvement of at least 75%. For health technology assessment purposes, we also estimated the budget impact of subsidies for SEC to a Government of the Philippines (GoP) payer. Deterministic and probabilistic sensitivity analyses were performed. Data sources included global literature and local intervention prices. RESULTS: All ILIs were more effective but also more expensive than MTX. In the base case, only IXE and SEC were cost-effective treatments at a gross domestic product-benchmarked threshold, yielding ICERs of PHP468 098.01 and PHP483 525.32 per PASI responder, respectively. GUS and UST were less likely to be cost-effective throughout a range of simulated thresholds. ICERs were most responsive to discontinuation rates and drug prices. Full subsidy of SEC for 5 years would cost the GoP PHP1.83 billion more than a similar subsidy for MTX. CONCLUSIONS: ILIs were clearly more effective than MTX, but only IXE and SEC were potentially cost-effective for a GoP payer. Any case in which SEC is fully subsidized is more expensive to the GoP than the base case. This study was limited by a lack of country-specific effectiveness data, underestimation of comparator costs, exclusion of noncutaneous and quality-of-life effects, and indirect costs.